// ECMAScript 2016  

// Array.prototype.includes ------------
// const array = [1, 'foo', NaN, undefined, false]
// console.log(array.indexOf('foo'))
// console.log(array.indexOf(1))
// console.log(array.indexOf(NaN))
// console.log(array.indexOf(undefined))
// console.log(array.indexOf(false))
// console.log(array.includes('foo'))
// console.log(array.includes(1))
// console.log(array.includes(NaN))
// console.log(array.includes(undefined))
// console.log(array.includes(false))

// 指数运算符 ------------------------

console.log(Math.pow(2, 10)) // 1024
console.log(2 ** 10) // 1024